Method for imparting topical holographic effect to a polymeric film substrate

Abstract

A method for imparting topical holographic effect to a polymeric film substrate comprising a first surface and a second surface. The method comprises the steps of embossing the first surface of the polymeric film substrate to impart a holographic effect to the polymeric film substrate; and printing the embossed first surface of the polymeric film substrate with ink and/or varnish on selected area which is intended not to have holographic effect and leaving the unprinted embossed area to provide a holographic effect.

1 . A method for imparting topical holographic effect to a polymeric film substrate, said polymeric film substrate comprising a first surface and a second surface, wherein said method comprising the steps of:
 (a) embossing the first surface of said polymeric film substrate to impart a holographic effect to the embossed area on the polymeric film substrate; and   (b) printing said embossed first surface of said polymeric film substrate with ink and/or varnish on selected area which is intended not to have holographic effect and leaving the unprinted embossed area to provide a holographic effect.   
     
     
         2 . The method of  claim 1 , wherein said polymeric film substrate is a transparent polymeric film substrate. 
     
     
         3 . The method of  claim 1 , wherein said first surface is embossed with a pattern of parallel and equally spaced fine grooves, said fine grooves being spaced apart from each other uniformly by about 0.1-10 microns and being at least 0.01 microns deep. 
     
     
         4 . The method of  claim 2 , wherein said transparent polymeric film substrate is selected from a group consisting of a polyethylene film, biaxially oriented polypropylene film and polyethylene teraphthalate film. 
     
     
         5 . The method of  claim 2 , wherein said embossed first surface of the polymeric film substrate is printed with varnish and said second surface of said polymeric film substrate is printed with ink. 
     
     
         6 . The method of  claim 5 , wherein the refractive indexes in the embossed area and the varnish-printed area on the first surface are substantially same. 
     
     
         7 . The method of  claim 5 , wherein the ink for printing the second surface containing reflective particles selected from the group consisting of aluminum particles, silver particles, gold particles, cobalt particles, chromium particles, platinum particles, palladium particles, nickel particles, carbon particles, aluminum oxides, titanium dioxide, iron oxides, zirconium oxide, zinc oxide, zinc sulfide, bismuth oxychloride, indium oxide, indium-tin-oxide, tantalum pentoxide, ceric oxide, yttrium oxide, europium oxide, hafnium nitride, hafnium carbide, hafnium oxide, lanthanum oxide, magnesium oxide, neodymium oxide, praseodymium oxide, samarium oxide, antimony trioxide, silicon carbide, silicon monoxide, selenium trioxide, tin oxide, tungsten trioxide, and mixtures thereof. 
     
     
         8 . The method of  claim 5 , wherein said unprinted embossed area on the first surface of the polymeric film substrate coincides with a printing element on the second surface of polymeric film substrate. 
     
     
         9 . The method of  claim 5 , wherein said polymeric film substrate is laminated to a second substrate selected from the group consisting of paper and a second polymeric film substrate. 
     
     
         10 . The method of  claim 10 , wherein said second substrate is a polyolefin film selected from the group consisting of a polyethlyene film and polypropylene film. 
     
     
         11 . The method of  claim 1 , wherein said embossing step is conducted at a temperature between the glass transition temperature and crystalline melting temperature of the polymer.